Vargo can't be sacrificed, including by your own effects and the game's mechanics. You can't sacrifice Vargo to your own Devour. You cannot use him to Combust, which is part of the cost.[2] If you play him from the void with a Haunting Scream, you do not sacrifice him at the end of the turn.

If you have twelve Vargos, and play another unit, you must sacrifice the unit you are playing. If you are trying to play another Vargo, you can't play it. You can't play Sites while you have eleven or more Vargos.[2]

Vargo dies to units with DeadlyDeadly: Kills any unit it damages., as long as he takes damage from that unit.[2]

Vargo Redclaw was the first card spoiled for Homecoming.[3] After the reveal, developer Patrick Chapin explained many of its unique interactions. He stated, "If you are thinking of ways units die without taking damage or losing health, they can't kill Vargo".[2]